DC to DC Charging

DIY
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1

I have a sailboat with the following set up

Wet Cell Golf Cart 12 V charged by solar . shore or alternator.

Li charged by DC to DC charger fed from the Golf Cart.

When the solar is running there is max 8 amps @ 14 volts. The DC to DC can support up to 50 amps.

When the solar is running how much current will the DC to DC output? 8 amps or 50 amps.

2

What dc to dc charger is it?

3

Victron Energy Orion XS 12/12-Volt 50 amp DC-DC

4

It might be worth limiting its output current in settings and making sure your input lockout is tight so you don’t drain the input battery side.

5

Wouldn’t the DC to DC shut down if the source dropped below 13.1 v

What I’m thinking is would the DC to DC run at full capacity if it saw a charging voltage irrespective of the charging current. So a low charging current of 10 amps could cause the golf cart battery to drain if the DC was pulling 40 amps..

If this is the case then the solar panel should be charging the Li battery directly not via to golf carts battery and DC to DC charger

6

If it is set like that. You mya have the scenario where the load of the orion may drop it as well to below that.

From what i see the orions do drop their charge rate depending on the input voltage if it does drop near cut off.

This is the scenario you want to avoid. So set the output max current to make sure it can’t.

  1. Load the battery and cause voltage sag and
  2. Cause a volt drop under load and so cut off.
  3. Drain the main bank faster than it is charging since the mppt is there to take care of that one anyway.